They are very numerous; mostly small, low, and level; sometimes
wooded, but always covered with verdure. Many are crescent-shaped;
others resemble a horse-shoe in figure. These last are nothing more
than narrow circles of land surrounding a smooth lagoon, connected by
a single opening with the sea. Some of the lagoons, said to have
subterranean outlets, have no visible ones; the inclosing island, in
such cases, being a complete zone of emerald. Other lagoons still,
are girdled by numbers of small, green islets, very near to each
other.

The origin of the entire group is generally ascribed to the coral
insect.

According to some naturalists, this wonderful little creature,
commencing its erections at the bottom of the sea, after the lapse of
centuries, carries them up to the surface, where its labours cease.
Here, the inequalities of the coral collect all floating bodies;
forming, after a time, a soil, in which the seeds carried thither by
birds germinate, and cover the whole with vegetation. Here and there,
all over this archipelago, numberless naked, detached coral
formations are seen, just emerging, as it were from the ocean. These
would appear to be islands in the very process of creation--at any
rate, one involuntarily concludes so, on beholding them.

As far as I know, there are but few bread-fruit trees in any part of
the Pomotu group. In many places the cocoa-nut even does not grow;
though, in others, it largely flourishes. Consequently, some of the
islands are altogether uninhabited; others support but a single
family; and in no place is the population very large. In some